When a valley is dammed, typically the timber is left standing as the valley fills with water leaving harvestable timber submerged. Applicant is aware of only one attempt in the prior art to harvest submerged timber, that being a hydraulically actuated pincer type cutter lowered from a crane. This prior art device is severely limited in the depth to which the cutter can be lowered in that the device once lowered has no remote maneuvering means and no remote vision systems so that the device must be maneuvered from the surface.
Applicant is aware of U.S. Pat. No. 3,667,515 which issued Jun. 6, 1972 to Corey for a Pile Cutting Device. Corey teaches a pile cutting device for use in locations remote from the operator. A pile cutter suspended on a cable is lowered by means of a crane to a desired depth, for example, to the bottom of a water body. The base of the pile cutting device is lowered so as to journal the pile in the base as base is lowered. The base has a guide across which is swept a selectively actuable blade. The blade shears the pile at its base.
Applicant is also aware of U.S. Pat. No. 3,693,676 which issued on Sep. 26, 1972 to Butch for an Underwater Pile Cutting Saw. Burch discloses a power saw capable of being manually manipulated above the surface of a body of water for cutting off pilings and the like adjacent to the bottom. A locater member engages around the piling or object to the cut and includes a post about which a saw swings, so as to swing across the locater member to cut off the piling or object. The locater member and saw may be manipulated from a boat, barge, dock or the like, it being an object of the Burch device to eliminate pilings and other objects adjacent the bottom as navigational hazards.
Applicant is further aware of U.S. Pat. No. 4,168,729 which issued Sep. 25, 1979 to Tausig et at for an Underwater Self-gripping Pile Cutting Device. As in the Corey device, Tausig et al teach a shearing pile cutter lowerable by means of a cable onto a pile. The shear cutter assembly has self-gripping teeth or spikes incorporated as part of the cutting blades to hold the pile and prevent slipping during cutting operations. As the hydraulically operated scissor-type cutter blades close about the pile, the spikes bite into the timber and keep the blades from squeezing off the pile.
None of the above devices are adapted for remotely controllable submersed logging. Consequently, it is an object of the present invention to provide a submersible device for cutting submersed timber, the device being maneuverable on a dam site floor and having remote vision means whereby the submersible device may be remotely and accurately maneuvered so as to engage a log cutting means against the submersed timber.